The Invention relates to a power split transmission, which is preferably used in agricultural tractors, wheel loaders, fork lift trucks, self driving agricultural and industrial vehicles etc. These types of transmissions are advantageous when having infinitely variable ratios, so that the vehicle speed can be adjusted independently on the engine speed. This allows great control of the engine power, for example to use maximum engine power for maximum profitability in time or for best fuel economy. Vehicles like tractors need a high efficiency of the trans-mission to get low fuel consumption. This drives the transmission concept to a power split design, which is a combination of a mechanical and a hydrostatic transmission. The concept of the transmission thereby is a key factor to achieve high fuel efficiency and low cost. The proposed concept gives a simple planetary design with high efficiency for dual yoke hydrostatic units, which for example are disclosed in the German Patent Application DE 10 2006 025 347. In these hydrostatic units the cylinder blocks of a pump and a motor of bent axis type are coupled by a common yoke. When the pump is varied from zero to maximum flow rate the motor is forced from maximum to minimum flow rate.